Field of the Invention
The present disclosure relates to a knee protection structure for a vehicle. More particularly, it relates to a knee protection structure for a vehicle, which is capable of meeting more stringent passenger injury conditions of a vehicle collision test, of simplifying an assembly process, and of achieving a reduction in manufacturing costs.
Description of Related Art
In general, when a vehicle is involved in a collision while traveling, passengers in the vehicle are pushed to a front crash pad by inertia.
Accordingly, vehicles are essentially equipped with passenger constraining devices, for example, air bags and seat belts, in order to protect passengers in the event of an accident.
However, although the air bag or seat belt protects approximately the portion of the passenger's body above the abdomen, there is the risk of a cowl crossbar, which is located below the inside of the crash pad, and a lower crash pad panel, which forms the lower portion of the crash pad, hitting the knees of the occupants (i.e. both the driver and front-seat passenger).
As a provision for the above-described problem, in order to reduce the extent of injury to the passenger's knee, conventionally, a knee bolster, which is a knee protection device, is provided below the inside of the crash pad.
The prior art (related art) discloses a knee protection device in which a “U”-shaped outer panel formed of a plastic material and a “U”-shaped inner panel formed of a steel material are installed to define a space therebetween and a shock-absorbing member capable of absorbing shocks is installed in the space.
However, the plastic outer panel is very brittle in consideration of the load generated upon a collision and knee penetration, thereby forming a sharp edge that may inflict an injury on the knee when it is broken, and the steel inner panel may prevent sufficient deformation of the shock absorbing member.
FIG. 1 is a perspective view illustrating another configuration of a knee protection structure for a vehicle according to the related art. A shock-absorbing foam 3 is coupled to a U-shaped bracket 2 which is installed at one side of a cowl crossbar 1, and a lower crash pad panel 5 and a knee bolster panel 4 formed of steel or Glass-fiber Mat reinforced Thermoplastics (GMT) are coupled at the front side thereof
Here, the lower crash pad panel 5 is manufactured of a polymer material such as, for example, polypropylene mineral filled (PPF) to cover the knee bolster panel 4 to impart a pleasant appearance, and the knee bolster panel 4, shock-absorbing foam 3, and U-shaped bracket 2 supporting the shock-absorbing foam 3 are sequentially arranged inside the lower crash pad panel 5.
With the configuration as described above, when the passenger's knee hits the lower crash pad panel 5 upon a front vehicle collision, the knee bolster panel 4 in the form of a steel body prevents additional knee penetration, and the shock-absorbing foam 3 located at the rear side thereof (i.e. the front side in terms of the front-and-rear direction of the vehicle) is deformed along with the U-shaped bracket 2 to absorb the energy of the shock.
However, since the lower crash pad panel 5 and the knee bolster panel 4 are installed separately from each other and the shock-absorbing foam 3 and the U-shaped bracket 2 are mounted, the related art has several problems including a complicated configuration and structure and high cost due to an increase in the number of components and hardware.
In addition, in the knee bolster device of the related art, although the steel knee bolster panel to control the penetration of the knee is mounted at the shock position of each of 50th percentile (50%) and 5th percentile (5%) dummies so as to prevent excessive penetration of the knee while allowing an increase in the load applied to the knee to some extent (i.e. up to 10 kN or less to satisfy the NCAP regulation), the knee bolster panel is considered a steel body in the US NCAP estimation, thereby increasing the knee load of the 50th percentile (50%) dummy. Therefore, it is difficult for the knee bolster panel to satisfy the regulation.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.